JNK2 Protein

JNK2 Protein — Mitogen-Activated Protein Kinase 9

Overview

Jnk2 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

JNK2 (c-Jun N-terminal Kinase 2), also known as MAPK9, is a serine/threonine-protein kinase belonging to the MAPK family. It plays critical roles in cellular stress responses, gene expression regulation, and neuronal survival. JNK2 is particularly important in the context of neurodegenerative diseases, where chronic activation contributes to neuronal death. [@weston2007]

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JNK2 Protein — Mitogen-Activated Protein Kinase 9

Overview

Jnk2 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

JNK2 (c-Jun N-terminal Kinase 2), also known as MAPK9, is a serine/threonine-protein kinase belonging to the MAPK family. It plays critical roles in cellular stress responses, gene expression regulation, and neuronal survival. JNK2 is particularly important in the context of neurodegenerative diseases, where chronic activation contributes to neuronal death. [@weston2007]

<div class="infobox infobox-protein"> [@thompson2021]
<table> [@zhang2022]
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">JNK2 Protein</th></tr> [@bogoyevitch2006]
<tr><td><strong>Protein Name</strong></td><td>Mitogen-Activated Protein Kinase 9</td></tr>
<tr><td><strong>Gene</strong></td><td>[MAPK9](/genes/jnk2)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P45985](https://www.uniprot.org/uniprot/P45985)</td></tr>
<tr><td><strong>PDB ID</strong></td><td>1JNK, 2NMP</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>48 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, Nucleus</td></tr>
<tr><td><strong>Protein Family</strong></td><td>MAPK family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/fibrosis" style="color:#ef9a9a">Fibrosis</a>, <a href="/wiki/inflammation" style="color:#ef9a9a">Inflammation</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">45 edges</a></td>
</tr>
</table>
</div>

Structure

JNK2 contains a kinase domain (residues 1-300) with the characteristic T-X-Y activation loop motif (Thr183-Tyr185). The protein has a C-terminal region involved in substrate binding and nuclear localization. JNK2 shares 83% sequence identity with JNK1 but has distinct tissue expression patterns and substrate specificities.

Normal Function

JNK2 is activated by various cellular stresses including:

• Oxidative stress: [ROS](/entities/reactive-oxygen-species)-induced activation
• Pro-inflammatory cytokines: TNF-α, IL-1β
• UV radiation: DNA damage response
• Protein misfolding: ER stress

Once activated, JNK2 phosphorylates multiple substrates:

• Transcription factors: c-Jun, ATF2, Elk-1
• Bcl-2 family proteins: Bim, BAD
• Synaptic proteins: PSD-95, Synapsin I

Role in Neurodegenerative Diseases

Alzheimer's Disease

JNK2/3 are chronically activated in Alzheimer's disease brains. Key mechanisms include:

• [Tau](/proteins/tau) pathology: JNK phosphorylates tau at multiple sites (Thr181, Ser202, Thr231), promoting NFT formation
• [Amyloid-beta](/proteins/amyloid-beta) toxicity: Aβ oligomers activate JNK pathway, leading to synaptic dysfunction
• Neuroinflammation: Microglial activation triggers JNK-mediated inflammatory responses

Parkinson's Disease

JNK activation mediates dopaminergic neuron death in PD:

• Mitochondrial dysfunction: JNK contributes to complex I inhibition-induced [apoptosis](/entities/apoptosis)
• [α-Synuclein](/proteins/alpha-synuclein) toxicity: JNK is activated by α-synuclein aggregates
• Neuroinflammation: Microglial JNK signaling promotes dopaminergic degeneration

Amyotrophic Lateral Sclerosis

JNK2 participates in motor neuron degeneration through:

• Excitotoxicity: Glutamate-induced JNK activation
• Oxidative stress: SOD1 mutations trigger JNK-mediated apoptosis

Therapeutic Targeting

Several JNK inhibitors are in development:

• SP600125: Broad JNK inhibitor (phase I)
• CC-90009: Novel JNK3-selective inhibitor
• AS601245: Neuroprotective JNK inhibitor

See Also

• [JNK1 Protein](/proteins/jnk1-protein)
• [JNK3 Protein](/proteins/jnk3-protein)
• [MAPK Signaling Pathway](/mechanisms/mapk-signaling-neurodegeneration))
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

Overview

Jnk2 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Background

The study of Jnk2 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

References

[Unknown, Davis RJ. Signal transduction by the JNK group of MAP kinases (2020) (2020)](https://doi.org/10.1016/j.cell.2020.03.012)

[Unknown, Weston CR, Davis RJ. The JNK signal transduction pathway (2007) (2007)](https://doi.org/10.1016/j.gde.2007.05.002)

[Thompson BJ, Bhattacharya K, Meijer M, et al., JNK signaling in Alzheimer's disease (2021) (2021)](https://doi.org/10.1111/jnc.15356)

[Zhang Y, Wang J, Cheng J, et al., Role of JNK in Parkinson's disease (2022) (2022)](https://doi.org/10.1002/mds.28921)

[Unknown, Bogoyevitch MA, Kobe B. Uses for JNK: the many substrates of the c-Jun N-terminal kinases (2006) (2006)](https://doi.org/10.1021/cr050533e)